Mann said Johnson had jumped from a second-story building in the 4500 block of Colfax Avenue. Johnson was taken to Cedars-Sinai Medical Center, Mann said, but the extent of his injuries was unknown.

It was not immediately clear what triggered Johnson's actions, Mann said.

According to the Wu-Tang Clan's website, rapper RZA discovered the Long Beach-based Northstar outside an L.A. radio station in 1998. On Tuesday, Johnson posted on Facebook and Twitter links to a new music video with rapper Rugged Monk.